The invention relates to a tissue microarrayer for arraying frozen tissue samples and a method of using the same. The device may be operated automatically, semi-automatically, or manually.
Tissue microarrays increase the throughput of molecular analyses by simultaneously arraying proteins, nucleic acids, and other biomolecules. Methods of generating tissue microarrays generally include removing tissue slices or cores from paraffin blocks and re-embedding these. For example, Battifora, Laboratory Investigation, 55: 244-248, 1986; and U.S. Pat. No. 4,820, 504, teaches forming multiple tissue samples into rods, bundling the rods into a casing, embedding the encased rods in paraffin and sectioning them. Although the method arrays multiple tissue samples, it is difficult to determine the identity of tissues within the array.
In U.S. Pat. No. 5,002,377, Battifora describes cutting tissue samples into strips, positioning the strips into parallel grooves in a mold, and embedding the strips in paraffin. Embedded strips are stacked, forming an embedded block comprising multiple tissue samples. The method is time consuming and is performed manually.
An automatic tissue microarrayer is described in U.S. Pat. No. 6,103,518, the entirety of which is incorporated herein by reference. The arrayer comprises two hollow needle punches; one for punching a hole in a recipient block comprising paraffin and one for removing a core of paraffin-embedded tissue from a sample or donor block. A stylet is used to remove the core of tissue from the donor punch and to push the core of tissue into the hole left in the recipient block. A different stylet is used to remove embedding matrix from the recipient punch so that it can be reused. The stylet is in communication with a stylet driver which controls its movement. The device and stylets described in U.S. Pat. No. 6,103,518 can be used to array multiple tissue samples; however, the device is not designed to optimally array a plurality of frozen tissue samples. Similarly, the stylet used with the device is subject to breakage upon repeated use in arraying frozen tissues.
The invention provides a device for microarraying tissue samples which is particularly suited for arraying frozen tissue samples. In one embodiment, the device comprises a cooling chamber for receiving at least one frozen material and for maintaining the frozen material in a frozen condition. The cooling chamber is moveable in an x- and y-direction relative to a horizontal surface. The device further comprises at least one coring needle which comprises a cutting surface and a lumen for receiving a core of frozen material cut by the cutting surface. In one embodiment, the device comprises at least one coring needle positioning element for positioning the at least one coring needle over said frozen material for cutting said frozen material. The coring needle can core either, or both, of a frozen tissue sample or frozen embedding matrix.
In another embodiment of the invention, the coring needle is in communication with a stylet, the stylet for ejecting the frozen material from the lumen of the coring needle. In one embodiment, the stylet comprises a stylet needle having a pushing surface and the stylet needle slidably fits within the lumen of the coring needle.
In another embodiment, device further comprises a processor in communication with the positioning element, and the processor controls the movement of the coring needle. In a further embodiment, .the device further comprises a processor in communication with the stylet and controls the movement of the stylet.
In one embodiment, the positioning element is moveable in an x-direction relative to a fixed horizontal surface positioned beneath the cooling chamber. In another embodiment, the positioning element is moveable in a y-direction relative to a fixed horizontal surface positioned beneath said cooling chamber. In a further embodiment, the device further comprises at least one platform, moveable in an x- or y-direction relative to a fixed horizontal surface positioned beneath the cooling chamber, and the at least one platform is between the cooling chamber and the fixed horizontal surface. In still another embodiment, the at least one platform comprises a first and a second platform. The first platform is moveable in an x-direction, while the second platform is moveable in a y-direction relative to the fixed horizontal surface.
In one embodiment, the device comprises a first and second coring needle, the first coring needle for receiving a frozen tissue sample from a block of frozen tissue, the second coring needle for receiving frozen embedding matrix from a block of frozen embedding matrix.
In one embodiment, the at least one positioning element comprises a recess for receiving the at least one coring needle and the at least one coring needle is capable of rotating within the recess of said at least one positioning element. In another embodiment, the device comprises a first positioning element for receiving a first coring needle and a second positioning element for receiving a second coring needle. In a further embodiment, the first and second positioning element are coupled to a holder. In still a further embodiment, the first and second positioning elements move in identical increments.
In one embodiment, the at least one positioning element is coupled to an x-direction slide element for moving the at least one positioning element in an x-direction relative to a fixed horizontal surface. In another embodiment, the at least one positioning element is coupled to a z-direction slide element. In a further embodiment, the z-direction slide element is coupled to a z-direction slide plate and is slidable along the z-direction slide plate in a z-direction. In still a further embodiment, the z-direction slide plate is coupled to the horizontal surface. In one embodiment, the x-direction slide is coupled to an x-direction slide plate and is slideable along the x-direction slide plate in an x-direction.
In one embodiment of the invention, when the first positioning element is positioned over a frozen tissue sample, the second positioning element is positioned over a block of frozen embedding matrix. In another embodiment, the device further comprises a moveable bridge for supporting a block of first frozen material over a block of second frozen material (e.g., a block of donor tissue over a block of frozen embedding matrix).
In one embodiment, the device comprises at least one motor for driving the movement of at least one moveable element of the device. In another embodiment, the at least one motor is in communication with a processor which is connectable to the network.
In one embodiment, the cooling chamber is sized to receive a donor block comprising a frozen tissue sample and a recipient block comprising frozen embedding matrix. In one embodiment, the donor and recipient block are contained within a retaining chamber within the cooling chamber.
In one embodiment, the device comprises a platform beneath the cooling chamber and a processor in communication with the platform controls the movement of the platform. In one embodiment, the device further comprises an input unit in communication with the processor. In this embodiment, when a user inputs coordinates into said input unit, the processor moves the at least one platform to the inputted coordinates.
The invention further provides a method of arraying frozen tissues comprising: providing a donor block comprising a frozen tissue sample, providing a recipient block comprising a frozen embedding matrix (the recipient block having at least one hole for receiving a core of frozen tissue), obtaining a core of frozen tissue from the donor block, and placing the core of tissue in the hole in the recipient block. In one embodiment, the method further comprises the step of placing the donor and recipient blocks in a cooling chamber. In one embodiment, the step of obtaining the core of frozen tissue comprises coring the frozen tissue with a coring needle. In another embodiment, the method further comprises: obtaining a section of tissue from the donor block, identifying coordinates of a tissue sample of interest in the section; and obtaining the core of frozen tissue from a portion of the donor block comprising identical coordinates. In one embodiment, the identifying is performed using a microscope. In another embodiment, the tissue sample of interest comprises abnormally proliferating cells. In a further embodiment, the tissue sample of interest comprises at least one cell expressing a heterogeneously expressed biomolecule.
In one embodiment, the method of arraying frozen tissues comprises providing a donor block comprising a frozen tissue sample, providing a recipient block comprising a frozen embedding matrix, creating at least one hole in the recipient block for receiving a core of frozen tissue, obtaining a core of frozen tissue from the donor block, and placing the core of tissue in the hole in said recipient block. In one embodiment, the steps of obtaining the core from the donor block and creating the hole in the recipient block are performed simultaneously. In another embodiment, the steps of obtaining the core from the donor block and creating the hole in the recipient block are performed sequentially. In a further embodiment, the method is at least partially automated.
The invention further provides microarray blocks for generating a plurality of microarrays. In one embodiment, the microarray block comprises a block of frozen embedding matrix comprising a plurality of holes, each hole filled with a frozen tissue sample. In one embodiment, the plurality of holes comprise tissue samples from at least two different organs of a single individual. In a further embodiment, the plurality of holes comprise tissue samples from at least five different organs of a single individual.
In one embodiment, the microarray block comprises at least one hole filled with a core of tissue comprising abnormally proliferating cells. In another embodiment, the microarray block comprises at least one tissue core at least 0.6 mm in diameter, at least 2 mm in diameter, or larger than 2 mm in diameter. In one embodiment, at least one tissue core comprises non-cancerous tissues.
In one embodiment, the microarray block comprises at least one tissue core from a human, from a plant, and/or from a non-human mammal. In one embodiment, at least one tissue core is from an organism selected from the group consisting of: dictostyelium, hydra, a nematode, a fruit fly, zebrafish, a frog, a mouse, a rat, a rabbit, a cat, a dog, a primate, and a plant. In another embodiment, the plurality of tissue cores comprise a plurality of different tissues"" at different developmental stages. In a further embodiment, the microarray block comprises cores of tissue from population of individuals. In still a further embodiment, the microarray block comprises cores of tissues representing different stages of a disease, such as cancer.
In one embodiment, the microarray block is further associated with an identifier, and information relating to the identifier stored within a database. In one embodiment, the information comprises information relating to the source of each tissue core within the microarray.
In one embodiment, the microarray block comprises tissue from at least one organism comprising an exogenous nucleic acid sequence which has been introduced into said organism. In another embodiment, the organism is a transgenic animal or plant. In one embodiment, the organism is a knock-out mouse or a knock-in mouse. In another embodiment, the microarray comprises a plurality of tissue samples, each tissue sample expressing different doses of a gene.